It is responsible for the difficulty of buying and selling to make use of it, however, which I assumed is what he meant. As for BTC transaction time, well, there are many different, widely used cryptocoins (e.g. Ethereum) out there. Anyways, it can be pretty much instant, it depends on the fee you are willing to spend. The costs and the satoshis required are also not static. Today you may need only 1 sat / vB to have your transaction confirmed in 5-10 minutes, and 10 sat / vB a week from now. If you have issues with taking a long ass time to get it confirmed, increase the fee. You may have it confirmed instantly just for 0.5 EUR. Judging by the stats, BTC seems chill these days, so it shouldn't cost too much, and it should get confirmed relatively quickly.